At the shoot-out at the MIT campus, which involved both of the Boston Marathon bombing suspects, MIT officer Sean Collier was killed and another officer, Richard Donahue, was wounded in the firefight and remains in critical condition. NBC's Ron Allen reports.

By Elizabeth Chuck and Miranda Leitsinger, NBC News

A young college police officer beloved by his colleagues has been identified by authorities as the latest casualty of the Boston Marathon bombing suspects.

Sean Collier, 27, of Somerville, Mass., was an officer at the Massachusetts Institute of Technology. He was found shot in his vehicle on the campus late Thursday night as authorities pursued two brothers named as suspects in Monday's deadly marathon attack.

In a statement his family said they were "heartbroken."

"Our only solace is that Sean died bravely doing what he committed his life to — serving and protecting others," the statement read. "We are thankful for the outpouring of support and condolences offered by so many people. We are grieving his loss and ask that the media respect our privacy at this time."

MIT Police Chief John DiFava described Collier as "a dedicated officer who was extremely well liked by his colleagues and the MIT community" in a press release on Friday.

“Sean was one of these guys who really looked at police work as a calling,” DiFava said. “He was born to be a police officer.”

Collier sustained multiple gunshot wounds, according to the Middlesex District Attorney in Massachusetts. He was transported to Massachusetts General Hospital, where he was pronounced dead.

Collier crossed paths with the two suspects, Dzhokhar and Tamerlan Tsarnaev, at approximately 10:20 p.m. Thursday night, authorities said — roughly five hours after the FBI released surveillance photos of the two men they say planted twin bombs near the finish line of Monday's Boston Marathon, killing three people and wounding 176.

The suspects shot Collier on the MIT campus in Cambridge, Mass., following an altercation, according to authorities. They then allegedly carjacked a Mercedes SUV, holding the driver hostage for a half hour before freeing him at a gas station in Cambridge, according to sources.

On their way to the neighboring town of Watertown, they tossed explosive devices outside the SUV’swindow, officials said. In a long exchange of gunfire between the suspects and authorities, a transit officer, Richard Donahue, was seriously injured.

The older brother, Tamerlan, died after the gun battle early Friday morning. The younger sibling, Dzhokhar, was captured at about 8:45 p.m. Friday following a large manhunt.

In a tragic coincidence, Collier and Donahue were "actually really good friends” who graduated from the same 26-member police academy class together three years ago, according to Milton, Mass., police officer Michael Delaney, who went to the academy with them.

"It's bizarre," Delaney said. "To take two of them out of there, it's a decent percentage."

Delaney, 36, said both Collier and Donahue lived in Somerville. He remembered Collier as a "technology nerd."

"He was definitely the smartest kid in the class. He built us a website that the instructors didn't know about, but we used as a forum to communicate with each other outside of class." Delaney said. "Sometimes [the teachers] weren't so clear on the instructions. It helped ensure that no one screwed up."

Delaney said he heard on the news last night that an MIT officer had been shot, and he immediately texted Collier. When his friend didn't text back, he started to worry. Hours later, he found out from a Facebook group he and other police officers from the academy are in that Collier was shot.

"I don't even think his family knew at that point," he said. "He was a really nice kid.”

Collier, who wasn't married, had only been a patrol officer at MIT since Jan. 9, 2012, according to the university. He was part of the MIT Outing club, which went on ski and hiking trips.

Noel Morales, a senior at MIT, said Collier was a regular presence at student events, eager to get to know the students he was protecting, according to MIT's press release.

“He was always really fun to hang out with,” Morales said.

Mechanical engineering student Matthew Gilbertson, who knew Collier from the Outing Club, said he and Collier were in a car accident a few months ago while driving to the White Mountains in New Hampshire.

“Sean was the first out of our car to go check and see if the [other driver] was OK,” said Andrew Ding, according to MIT's press release. “It would be exceedingly difficult to imagine him not stepping up and doing the right thing when he had the chance, which unfortunately he did last night.”

Somerville Alderman Bob Trane said he had been bombarded with phone calls from people wanted to express their condolences about Collier.

Miranda Leitsinger / NBC News

From left: Gary Grandonico, Max Jaffe, and Tomas Isman, all 22 and students at Tufts University, lived a few doors down from Collier but didn't know him. Asked why they were had hung a flag, Jaffe said: "In solidarity. We didn't really know the police officer who got killed this morning, but we wanted to show our support."

"We are all feeling the loss," Trane said from a block away from where Collier lived. "He was wise beyond his years. I was just impressed by how he was so mature for his age."

Before working for MIT, Collier was an IT civilian employee at the Somerville police department.

MIT's president said his death reverberated throughout the entire university community.

“The loss of Officer Collier is deeply painful to the entire MIT community,” L. Rafael Reif said,adding that it was "senseless and tragic."

The school's executive vice president and treasure, Israel Ruiz, said, “The MIT Police serve all of us at the Institute with great dignity, honor and dedication. Everyone here — those who knew Officer Collier, and those who did not — are devastated by the events that transpired on our campus last night. We will never forget the seriousness with which he took his role protecting MIT and those of us who consider it home.”

Authorities cordoned off Collier's home with yellow tape on Friday morning.

Collier's family asked for donations to be made in his name to The Jimmy Fund, which supports the Dana-Farber Cancer Institute in Boston.